package com.guangyunl.k_exam;
// 测试类
public class test13 {
    public static void main(String[] args){
        NoteBook noteBook = new NoteBook();
        Mouse mouse = new Mouse();
        KeyBoard keyBoard = new KeyBoard();

        noteBook.start();
        noteBook.useUSB(mouse);
        System.out.println("======================");
        noteBook.useUSB(keyBoard);

        noteBook.start();

    }
}
